/*
 * Copyright 2016-2023 The OSHI Project Contributors
 * SPDX-License-Identifier: MIT
 */
package oshi.hardware;

import static oshi.util.Memoizer.memoize;

import java.util.List;
import java.util.Locale;
import java.util.Objects;
import java.util.Properties;
import java.util.function.Supplier;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import oshi.annotation.concurrent.Immutable;
import oshi.annotation.concurrent.ThreadSafe;
import oshi.software.os.OSProcess;
import oshi.software.os.OSThread;
import oshi.util.Constants;
import oshi.util.FileUtil;
import oshi.util.ParseUtil;
import oshi.util.Util;

/**
 * This class represents the entire Central Processing Unit (CPU) of a computer system, which may contain one or more
 * physical packages (sockets), one or more physical processors (cores), and one or more logical processors (what the
 * Operating System sees, which may include hyperthreaded cores.)
 */
@ThreadSafe
public interface CentralProcessor {

    /**
     * The CPU's identifier strings ,including name, vendor, stepping, model, and family information (also called the
     * signature of a CPU).
     * <p>
     * The Processor Identifier is primarily associated with Intel-based chips. Attempts are made to provide comparable
     * values for other chip manufacturers.
     *
     * @return a {@link ProcessorIdentifier} object encapsulating CPU identifier information.
     */
    ProcessorIdentifier getProcessorIdentifier();

    /**
     * Maximum frequeny (in Hz), of the logical processors on this CPU.
     *
     * @return The max frequency or -1 if unknown.
     */
    long getMaxFreq();

    /**
     * Attempts to return the current frequency (in Hz), of the logical processors on this CPU.
     * <p>
     * May not be implemented on all Operating Systems.
     * <p>
     * On Windows, returns an estimate based on the percent of maximum frequency. On Windows systems with more than 64
     * logical processors, may only return frequencies for the current processor group in the first portion of the
     * array.
     *
     * @return An array of processor frequencies for each logical processor on the system. Use the
     *         {@link #getLogicalProcessors()} to correlate these frequencies with physical packages and processors.
     */
    long[] getCurrentFreq();

    /**
     * Returns an {@code UnmodifiableList} of the CPU's logical processors. The list will be sorted in order of
     * increasing NUMA node number, and then processor number. This order is (usually) consistent with other methods
     * providing per-processor results.
     * <p>
     * On some operating systems with variable numbers of logical processors, the size of this array could change and
     * may not align with other per-processor methods.
     *
     * @return An {@code UnmodifiabeList} of logical processors.
     */
    List<LogicalProcessor> getLogicalProcessors();

    /**
     * Returns an {@code UnmodifiableList} of the CPU's physical processors. The list will be sorted in order of
     * increasing core ID.
     *
     * @return An {@code UnmodifiabeList} of physical processors.
     */
    List<PhysicalProcessor> getPhysicalProcessors();

    /**
     * Makes a best-effort attempt to identify the CPU's processor caches. For hybrid processors, both performance and
     * efficiency core caches are shown. Only one instance of per-core caches is shown.
     * <p>
     * Values are unreliable in virtual machines and rely in information made available by the VM or hypervisor. Callers
     * should conduct sanity checking of the returned objects. Not all values are available on all operating systems or
     * architectures.
     * <p>
     * Not available on Solaris.
     *
     * @return An {@code UnmodifiabeList} of processor caches.
     */
    List<ProcessorCache> getProcessorCaches();

    /**
     * Returns the "recent cpu usage" for the whole system by counting ticks from {@link #getSystemCpuLoadTicks()}
     * between the user-provided value from a previous call.
     * <p>
     * On some operating systems with variable numbers of logical processors, the size of the array returned from a
     * previous call to {@link #getSystemCpuLoadTicks()} could change and will throw an
     * {@link IllegalArgumentException}. Calling code on these operating systems should handle this exception.
     *
     * @param oldTicks A tick array from a previous call to {@link #getSystemCpuLoadTicks()}
     * @return CPU load between 0 and 1 (100%)
     * @throws IllegalArgumentException if the array sizes differ.
     */
    double getSystemCpuLoadBetweenTicks(long[] oldTicks);

    /**
     * Get System-wide CPU Load tick counters. Returns an array with eight elements representing milliseconds spent in
     * User (0), Nice (1), System (2), Idle (3), IOwait (4), Hardware interrupts (IRQ) (5), Software interrupts/DPC
     * (SoftIRQ) (6), or Steal (7) states. Use {@link oshi.hardware.CentralProcessor.TickType#getIndex()} to retrieve
     * the appropriate index. By measuring the difference between ticks across a time interval, CPU load over that
     * interval may be calculated.
     * <p>
     * On some operating systems with variable numbers of logical processors, the size of this array could change and
     * may not align with other per-processor methods.
     * <p>
     * Note that while tick counters are in units of milliseconds, they may advance in larger increments along with
     * (platform dependent) clock ticks. For example, by default Windows clock ticks are 1/64 of a second (about 15 or
     * 16 milliseconds) and Linux ticks are distribution and configuration dependent but usually 1/100 of a second (10
     * milliseconds).
     * <p>
     * Nice and IOWait information is not available on Windows, and IOwait and IRQ information is not available on
     * macOS, so these ticks will always be zero.
     * <p>
     * To calculate overall Idle time using this method, include both Idle and IOWait ticks. Similarly, IRQ, SoftIRQ,
     * and Steal ticks should be added to the System value to get the total. System ticks also include time executing
     * other virtual hosts (steal).
     *
     * @return An array of 8 long values representing time spent in User, Nice, System, Idle, IOwait, IRQ, SoftIRQ, and
     *         Steal states.
     */
    long[] getSystemCpuLoadTicks();

    /**
     * Returns the system load average for the number of elements specified, up to 3, representing 1, 5, and 15 minutes.
     * The system load average is the sum of the number of runnable entities queued to the available processors and the
     * number of runnable entities running on the available processors averaged over a period of time.
     * <p>
     * This method is designed to provide a hint about the system load and may be queried frequently.
     * <p>
     * The way in which the load average is calculated is operating system specific but is typically a damped
     * time-dependent average. Linux includes processes waiting for system resources such as disks, while macOS and Unix
     * consider only processes waiting for CPU.
     * <p>
     * Windows does not provide a load average. Users may set the configuration property
     * {@code oshi.os.windows.loadaverage} to {@code true} to start a daemon thread which will provide a similar metric.
     * <p>
     * The load average may be unavailable on some platforms (e.g., Windows without the above configuration). If the
     * load average is not available, a negative value is returned.
     *
     * @param nelem Number of elements to return.
     * @return an array of the system load averages for 1, 5, and 15 minutes with the size of the array specified by
     *         nelem; or negative values if not available.
     */
    double[] getSystemLoadAverage(int nelem);

    /**
     * This is a convenience method which collects an initial set of ticks using {@link #getSystemCpuLoadTicks()} and
     * passes that result to {@link #getSystemCpuLoadBetweenTicks(long[])} after the specified delay.
     *
     *
     * @param delay Milliseconds to wait.
     * @return value between 0 and 1 (100%) that represents the cpu usage in the provided time period.
     */
    default double getSystemCpuLoad(long delay) {
        long start = System.nanoTime();
        long[] oldTicks = getSystemCpuLoadTicks();
        long toWait = delay - (System.nanoTime() - start) / 1_000_000;
        // protect against IllegalArgumentException
        if (toWait > 0L) {
            Util.sleep(delay);
        }
        return getSystemCpuLoadBetweenTicks(oldTicks);
    }

    /**
     * This is a convenience method which collects an initial set of ticks using {@link #getProcessorCpuLoadTicks()} and
     * passes that result to {@link #getProcessorCpuLoadBetweenTicks(long[][])} after the specified delay.
     * <p>
     * On some operating systems with variable numbers of logical processors, the size of the array returned from the
     * two calls could change and will throw an {@link IllegalArgumentException}. Calling code on these operating
     * systems should handle this exception.
     *
     * @param delay Milliseconds to wait.
     * @return array of CPU load between 0 and 1 (100%) for each logical processor, for the provided time period.
     * @throws IllegalArgumentException if the array sizes differ between calls.
     */
    default double[] getProcessorCpuLoad(long delay) {
        long start = System.nanoTime();
        long[][] oldTicks = getProcessorCpuLoadTicks();
        long toWait = delay - (System.nanoTime() - start) / 1_000_000;
        // protect against IllegalArgumentException
        if (toWait > 0L) {
            Util.sleep(delay);
        }
        return getProcessorCpuLoadBetweenTicks(oldTicks);
    }

    /**
     * Returns the "recent cpu usage" for all logical processors by counting ticks from
     * {@link #getProcessorCpuLoadTicks()} between the user-provided value from a previous call.
     * <p>
     * On some operating systems with variable numbers of logical processors, the size of the array returned from the
     * two calls could change and will throw an {@link IllegalArgumentException}. Calling code on these operating
     * systems should handle this exception.
     *
     * @param oldTicks A tick array from a previous call to {@link #getProcessorCpuLoadTicks()}
     * @return array of CPU load between 0 and 1 (100%) for each logical processor
     * @throws IllegalArgumentException if the array sizes differ between calls.
     */
    double[] getProcessorCpuLoadBetweenTicks(long[][] oldTicks);

    /**
     * Get Processor CPU Load tick counters. Returns a two dimensional array, with {@link #getLogicalProcessorCount()}
     * arrays, each containing seven elements representing milliseconds spent in User (0), Nice (1), System (2), Idle
     * (3), IOwait (4), Hardware interrupts (IRQ) (5), Software interrupts/DPC (SoftIRQ) (6), or Steal (7) states. Use
     * {@link oshi.hardware.CentralProcessor.TickType#getIndex()} to retrieve the appropriate index. By measuring the
     * difference between ticks across a time interval, CPU load over that interval may be calculated.
     * <p>
     * Note that while tick counters are in units of milliseconds, they may advance in larger increments along with
     * (platform dependent) clock ticks. For example, by default Windows clock ticks are 1/64 of a second (about 15 or
     * 16 milliseconds) and Linux ticks are distribution and configuration dependent but usually 1/100 of a second (10
     * milliseconds).
     * <p>
     * Nice and IOwait per processor information is not available on Windows, and IOwait and IRQ information is not
     * available on macOS, so these ticks will always be zero.
     * <p>
     * To calculate overall Idle time using this method, include both Idle and IOWait ticks. Similarly, IRQ, SoftIRQ and
     * Steal ticks should be added to the System value to get the total. System ticks also include time executing other
     * virtual hosts (steal).
     *
     * @return A 2D array of logicalProcessorCount x 7 long values representing time spent in User, Nice, System, Idle,
     *         IOwait, IRQ, SoftIRQ, and Steal states.
     */
    long[][] getProcessorCpuLoadTicks();

    /**
     * Get the number of logical CPUs available for processing. This value may be higher than physical CPUs if
     * hyperthreading is enabled.
     * <p>
     * On some operating systems with variable numbers of logical processors, may return a max value.
     *
     * @return The number of logical CPUs available.
     */
    int getLogicalProcessorCount();

    /**
     * Get the number of physical CPUs/cores available for processing.
     * <p>
     * On some operating systems with variable numbers of physical processors available to the OS, may return a max
     * value.
     *
     * @return The number of physical CPUs available.
     */
    int getPhysicalProcessorCount();

    /**
     * Get the number of packages/sockets in the system. A single package may contain multiple cores.
     *
     * @return The number of physical packages available.
     */
    int getPhysicalPackageCount();

    /**
     * Get the number of system-wide context switches which have occurred.
     * <p>
     * Not available system-wide on macOS. Process- and Thread-level context switches are available from
     * {@link OSProcess#getContextSwitches()} and {@link OSThread#getContextSwitches()}.
     *
     * @return The number of context switches, if this information is available; 0 otherwise.
     */
    long getContextSwitches();

    /**
     * Get the number of system-wide interrupts which have occurred.
     * <p>
     * Not available system-wide on macOS.
     *
     * @return The number of interrupts, if this information is available; 0 otherwise.
     */
    long getInterrupts();

    /**
     * Index of CPU tick counters in the {@link #getSystemCpuLoadTicks()} and {@link #getProcessorCpuLoadTicks()}
     * arrays.
     */
    enum TickType {
        /**
         * CPU utilization that occurred while executing at the user level (application).
         */
        USER(0),
        /**
         * CPU utilization that occurred while executing at the user level with nice priority.
         */
        NICE(1),
        /**
         * CPU utilization that occurred while executing at the system level (kernel).
         */
        SYSTEM(2),
        /**
         * Time that the CPU or CPUs were idle and the system did not have an outstanding disk I/O request.
         */
        IDLE(3),
        /**
         * Time that the CPU or CPUs were idle during which the system had an outstanding disk I/O request.
         */
        IOWAIT(4),
        /**
         * Time that the CPU used to service hardware IRQs
         */
        IRQ(5),
        /**
         * Time that the CPU used to service soft IRQs
         */
        SOFTIRQ(6),
        /**
         * Time which the hypervisor dedicated for other guests in the system. Only supported on Linux and AIX
         */
        STEAL(7);

        private final int index;

        TickType(int value) {
            this.index = value;
        }

        /**
         * @return The integer index of this ENUM in the processor tick arrays, which matches the output of Linux
         *         /proc/cpuinfo
         */
        public int getIndex() {
            return index;
        }
    }

    /**
     * A class representing a Logical Processor and its replationship to physical processors, physical packages, and
     * logical groupings such as NUMA Nodes and Processor groups, useful for identifying processor topology.
     */
    @Immutable
    class LogicalProcessor {
        private final int processorNumber;
        private final int physicalProcessorNumber;
        private final int physicalPackageNumber;
        private final int numaNode;
        private final int processorGroup;

        /**
         * @param processorNumber         the Processor number
         * @param physicalProcessorNumber the core number
         * @param physicalPackageNumber   the package/socket number
         */
        public LogicalProcessor(int processorNumber, int physicalProcessorNumber, int physicalPackageNumber) {
            this(processorNumber, physicalProcessorNumber, physicalPackageNumber, 0, 0);
        }

        /**
         * @param processorNumber         the Processor number
         * @param physicalProcessorNumber the core number
         * @param physicalPackageNumber   the package/socket number
         * @param numaNode                the NUMA node number
         */
        public LogicalProcessor(int processorNumber, int physicalProcessorNumber, int physicalPackageNumber,
                int numaNode) {
            this(processorNumber, physicalProcessorNumber, physicalPackageNumber, numaNode, 0);
        }

        /**
         * @param processorNumber         the Processor number
         * @param physicalProcessorNumber the core number
         * @param physicalPackageNumber   the package/socket number
         * @param numaNode                the NUMA node number
         * @param processorGroup          the Processor Group number
         */
        public LogicalProcessor(int processorNumber, int physicalProcessorNumber, int physicalPackageNumber,
                int numaNode, int processorGroup) {
            this.processorNumber = processorNumber;
            this.physicalProcessorNumber = physicalProcessorNumber;
            this.physicalPackageNumber = physicalPackageNumber;
            this.numaNode = numaNode;
            this.processorGroup = processorGroup;
        }

        /**
         * The Logical Processor number as seen by the Operating System. Used for assigning process affinity and
         * reporting CPU usage and other statistics.
         *
         * @return the processorNumber
         */
        public int getProcessorNumber() {
            return processorNumber;
        }

        /**
         * The physical processor (core) id number assigned to this logical processor. Hyperthreaded logical processors
         * which share the same physical processor will have the same number.
         *
         * @return the physicalProcessorNumber
         */
        public int getPhysicalProcessorNumber() {
            return physicalProcessorNumber;
        }

        /**
         * The physical package (socket) id number assigned to this logical processor. Multicore CPU packages may have
         * multiple physical processors which share the same number.
         *
         * @return the physicalPackageNumber
         */
        public int getPhysicalPackageNumber() {
            return physicalPackageNumber;
        }

        /**
         * The NUMA node. If the operating system supports Non-Uniform Memory Access this identifies the node number.
         * Set to 0 if the operating system does not support NUMA. Not supported on macOS or FreeBSD.
         *
         * @return the NUMA Node number
         */
        public int getNumaNode() {
            return numaNode;
        }

        /**
         * The Processor Group. Only applies to Windows systems with more than 64 logical processors. Set to 0 for other
         * operating systems or Windows systems with 64 or fewer logical processors.
         *
         * @return the processorGroup
         */
        public int getProcessorGroup() {
            return processorGroup;
        }

        @Override
        public String toString() {
            return "LogicalProcessor [processorNumber=" + processorNumber + ", coreNumber=" + physicalProcessorNumber
                    + ", packageNumber=" + physicalPackageNumber + ", numaNode=" + numaNode + ", processorGroup="
                    + processorGroup + "]";
        }
    }

    /**
     * A class representing a Physical Processor (a core) providing per-core statistics that may vary, particularly in
     * hybrid/modular processors.
     */
    @Immutable
    class PhysicalProcessor {
        private final int physicalPackageNumber;
        private final int physicalProcessorNumber;
        private final int efficiency;
        private final String idString;

        public PhysicalProcessor(int physicalPackageNumber, int physicalProcessorNumber) {
            this(physicalPackageNumber, physicalProcessorNumber, 0, "");
        }

        public PhysicalProcessor(int physicalPackageNumber, int physicalProcessorNumber, int efficiency,
                String idString) {
            this.physicalPackageNumber = physicalPackageNumber;
            this.physicalProcessorNumber = physicalProcessorNumber;
            this.efficiency = efficiency;
            this.idString = idString;
        }

        /**
         * Gets the package id. This is also the physical package number which corresponds to
         * {@link LogicalProcessor#getPhysicalPackageNumber()}.
         *
         * @return the physicalProcessorNumber
         */
        public int getPhysicalPackageNumber() {
            return physicalPackageNumber;
        }

        /**
         * Gets the core id. This is also the physical processor number which corresponds to
         * {@link LogicalProcessor#getPhysicalProcessorNumber()}.
         *
         * @return the physicalProcessorNumber
         */
        public int getPhysicalProcessorNumber() {
            return physicalProcessorNumber;
        }

        /**
         * Gets a platform specific measure of processor performance vs. efficiency, useful for identifying cores in
         * hybrid/System on Chip (SoC) processors such as ARM's big.LITTLE architecture, Apple's M1, and Intel's P-core
         * and E-core hybrid technology. A core with a higher value for the efficiency class has intrinsically greater
         * performance and less efficiency than a core with a lower value for the efficiency class.
         *
         * @return On Windows 10 and higher, returns the {@code EfficiencyClass} value from the
         *         {@code PROCESSOR_RELATIONSHIP} structure.
         *         <p>
         *         On macOS with Apple Silicon, emulates the same relative efficiency class values as Windows.
         *         <p>
         *         On Linux, returns the {@code cpu_capacity} value from sysfs. This is an optional cpu node property
         *         representing CPU capacity expressed in normalized DMIPS/MHz.
         *         <p>
         *         On OpenBSD, FreeBSD, and Solaris with ARM big.LITTLE processors, emulates the same relative
         *         efficiency class values as Windows.
         *         <p>
         *         For unimplemented operating systems or architectures, returns 0.
         * @see <a href=
         *      "https://docs.microsoft.com/en-us/windows/win32/api/winnt/ns-winnt-processor_relationship">PROCESSOR_RELATIONSHIP</a>
         * @see <a href=
         *      "https://www.kernel.org/doc/Documentation/devicetree/bindings/arm/cpu-capacity.txt">cpu-capacity</a>
         */
        public int getEfficiency() {
            return efficiency;
        }

        /**
         * Gets a platform specific identification string representing this core. This string requires user parsing to
         * obtain meaningful information. As this is an experimental feature, users should not rely on the format.
         *
         * @return On Windows, returns the per-core Processor ID (CPUID).
         *         <p>
         *         On macOS, returns a compatibility string from the IO Registry identifying hybrid cores.
         *         <p>
         *         On Linux, returns the {@code MODALIAS} value for the core's driver.
         *         <p>
         *         On OpenBSD, FreeBSD, and Solaris, returns a per-core CPU identification string.
         *         <p>
         *         For unimplemented operating systems, returns an empty string.
         */
        public String getIdString() {
            return idString;
        }

        @Override
        public String toString() {
            return "PhysicalProcessor [package/core=" + physicalPackageNumber + "/" + physicalProcessorNumber
                    + ", efficiency=" + efficiency + ", idString=" + idString + "]";
        }
    }

    /**
     * A class representing CPU Cache Memory.
     */
    @Immutable
    class ProcessorCache {

        /**
         * The type of cache.
         */
        public enum Type {
            UNIFIED, INSTRUCTION, DATA, TRACE;

            @Override
            public String toString() {
                return name().substring(0, 1) + name().substring(1).toLowerCase(Locale.ROOT);
            }
        }

        private final byte level;
        private final byte associativity;
        private final short lineSize;
        private final int cacheSize;
        private final Type type;

        public ProcessorCache(byte level, byte associativity, short lineSize, int cacheSize, Type type) {
            this.level = level;
            this.associativity = associativity;
            this.lineSize = lineSize;
            this.cacheSize = cacheSize;
            this.type = type;
        }

        public ProcessorCache(int level, int associativity, int lineSize, long cacheSize, Type type) {
            this((byte) level, (byte) associativity, (short) lineSize, (int) cacheSize, type);
        }

        /**
         * The cache level. This member can be 1 (L1), 2 (L2), 3 (L3), or 4 (L4).
         *
         * @return the level
         */
        public byte getLevel() {
            return level;
        }

        /**
         * The cache associativity. If this member is {@code 0xFF}, the cache is fully associative.
         *
         * @return the associativity
         */
        public byte getAssociativity() {
            return associativity;
        }

        /**
         * The cache line size, in bytes.
         *
         * @return the line size
         */
        public short getLineSize() {
            return lineSize;
        }

        /**
         * The cache size, in bytes.
         *
         * @return the cache size
         */
        public int getCacheSize() {
            return cacheSize;
        }

        /**
         * The cache type.
         *
         * @return the type
         */
        public Type getType() {
            return type;
        }

        @Override
        public String toString() {
            return "ProcessorCache [L" + level + " " + type + ", cacheSize=" + cacheSize + ", "
                    + (associativity > 0 ? associativity + "-way" : "unknown") + " associativity, lineSize=" + lineSize
                    + "]";
        }

        @Override
        public boolean equals(Object obj) {
            if (this == obj) {
                return true;
            }
            if (obj == null || !(obj instanceof ProcessorCache)) {
                return false;
            }
            ProcessorCache other = (ProcessorCache) obj;
            return associativity == other.associativity && cacheSize == other.cacheSize && level == other.level
                    && lineSize == other.lineSize && type == other.type;
        }

        @Override
        public int hashCode() {
            return Objects.hash(associativity, cacheSize, level, lineSize, type);
        }
    }

    /**
     * A class encapsulating ghe CPU's identifier strings ,including name, vendor, stepping, model, and family
     * information (also called the signature of a CPU)
     */
    @Immutable
    final class ProcessorIdentifier {
        private static final String OSHI_ARCHITECTURE_PROPERTIES = "oshi.architecture.properties";

        // Provided in constructor
        private final String cpuVendor;
        private final String cpuName;
        private final String cpuFamily;
        private final String cpuModel;
        private final String cpuStepping;
        private final String processorID;
        private final String cpuIdentifier;
        private final boolean cpu64bit;
        private final long cpuVendorFreq;

        private final Supplier<String> microArchictecture = memoize(this::queryMicroarchitecture);

        public ProcessorIdentifier(String cpuVendor, String cpuName, String cpuFamily, String cpuModel,
                String cpuStepping, String processorID, boolean cpu64bit) {
            this(cpuVendor, cpuName, cpuFamily, cpuModel, cpuStepping, processorID, cpu64bit, -1L);
        }

        public ProcessorIdentifier(String cpuVendor, String cpuName, String cpuFamily, String cpuModel,
                String cpuStepping, String processorID, boolean cpu64bit, long vendorFreq) {
            this.cpuVendor = cpuVendor.startsWith("0x") ? queryVendorFromImplementer(cpuVendor) : cpuVendor;
            this.cpuName = cpuName;
            this.cpuFamily = cpuFamily;
            this.cpuModel = cpuModel;
            this.cpuStepping = cpuStepping;
            this.processorID = processorID;
            this.cpu64bit = cpu64bit;

            // Build Identifier
            StringBuilder sb = new StringBuilder();
            if (cpuVendor.contentEquals("GenuineIntel")) {
                sb.append(cpu64bit ? "Intel64" : "x86");
            } else {
                sb.append(cpuVendor);
            }
            sb.append(" Family ").append(cpuFamily);
            sb.append(" Model ").append(cpuModel);
            sb.append(" Stepping ").append(cpuStepping);
            this.cpuIdentifier = sb.toString();

            if (vendorFreq > 0) {
                this.cpuVendorFreq = vendorFreq;
            } else {
                // Parse Freq from name string
                Pattern pattern = Pattern.compile("@ (.*)$");
                Matcher matcher = pattern.matcher(cpuName);
                if (matcher.find()) {
                    String unit = matcher.group(1);
                    this.cpuVendorFreq = ParseUtil.parseHertz(unit);
                } else {
                    this.cpuVendorFreq = -1L;
                }
            }
        }

        /**
         * Processor vendor.
         *
         * @return vendor string.
         */
        public String getVendor() {
            return cpuVendor;
        }

        /**
         * Name, eg. Intel(R) Core(TM)2 Duo CPU T7300 @ 2.00GHz
         *
         * @return Processor name.
         */
        public String getName() {
            return cpuName;
        }

        /**
         * Gets the family. For non-Intel/AMD processors, returns the comparable value, such as the Architecture.
         *
         * @return the family
         */
        public String getFamily() {
            return cpuFamily;
        }

        /**
         * Gets the model. For non-Intel/AMD processors, returns the comparable value, such as the Partnum.
         *
         * @return the model
         */
        public String getModel() {
            return cpuModel;
        }

        /**
         * Gets the stepping. For non-Intel/AMD processors, returns the comparable value, such as the rnpn composite of
         * Variant and Revision.
         *
         * @return the stepping
         */
        public String getStepping() {
            return cpuStepping;
        }

        /**
         * Gets the Processor ID. This is a hexidecimal string representing an 8-byte value, normally obtained using the
         * CPUID opcode with the EAX register set to 1. The first four bytes are the resulting contents of the EAX
         * register, which is the Processor signature, represented in human-readable form by {@link #getIdentifier()} .
         * The remaining four bytes are the contents of the EDX register, containing feature flags.
         * <p>
         * For processors that do not support the CPUID opcode this field is populated with a comparable hex string. For
         * example, ARM Processors will fill the first 32 bytes with the MIDR. AIX PowerPC Processors will return the
         * machine ID.
         * <p>
         * NOTE: The order of returned bytes is platform and software dependent. Values may be in either Big Endian or
         * Little Endian order.
         * <p>
         * NOTE: If OSHI is unable to determine the ProcessorID from native sources, it will attempt to reconstruct one
         * from available information in the processor identifier.
         *
         * @return A string representing the Processor ID
         */
        public String getProcessorID() {
            return processorID;
        }

        /**
         * Identifier, eg. x86 Family 6 Model 15 Stepping 10. For non-Intel/AMD processors, this string is populated
         * with comparable values.
         *
         * @return Processor identifier.
         */
        public String getIdentifier() {
            return cpuIdentifier;
        }

        /**
         * Is CPU 64bit?
         *
         * @return True if cpu is 64bit.
         */
        public boolean isCpu64bit() {
            return cpu64bit;
        }

        /**
         * Vendor frequency (in Hz), eg. for processor named Intel(R) Core(TM)2 Duo CPU T7300 @ 2.00GHz the vendor
         * frequency is 2000000000.
         *
         * @return Processor frequency or -1 if unknown.
         */
        public long getVendorFreq() {
            return cpuVendorFreq;
        }

        /**
         * Returns the processor's microarchitecture, if known.
         *
         * @return A string containing the microarchitecture if known. {@link Constants#UNKNOWN} otherwise.
         */
        public String getMicroarchitecture() {
            return microArchictecture.get();
        }

        private String queryMicroarchitecture() {
            String arch = null;
            Properties archProps = FileUtil.readPropertiesFromFilename(OSHI_ARCHITECTURE_PROPERTIES);
            // Intel is default, no prefix
            StringBuilder sb = new StringBuilder();
            // AMD and ARM properties have prefix
            String ucVendor = this.cpuVendor.toUpperCase(Locale.ROOT);
            if (ucVendor.contains("AMD")) {
                sb.append("amd.");
            } else if (ucVendor.contains("ARM")) {
                sb.append("arm.");
            } else if (ucVendor.contains("IBM")) {
                // Directly parse the name to POWER#
                int powerIdx = this.cpuName.indexOf("_POWER");
                if (powerIdx > 0) {
                    arch = this.cpuName.substring(powerIdx + 1);
                }
            } else if (ucVendor.contains("APPLE")) {
                sb.append("apple.");
            }
            if (Util.isBlank(arch) && !sb.toString().equals("arm.")) {
                // Append family
                sb.append(this.cpuFamily);
                arch = archProps.getProperty(sb.toString());
            }

            if (Util.isBlank(arch)) {
                // Append model
                sb.append('.').append(this.cpuModel);
                arch = archProps.getProperty(sb.toString());
            }

            if (Util.isBlank(arch)) {
                // Append stepping
                sb.append('.').append(this.cpuStepping);
                arch = archProps.getProperty(sb.toString());
            }

            return Util.isBlank(arch) ? Constants.UNKNOWN : arch;
        }

        private String queryVendorFromImplementer(String cpuVendor) {
            Properties archProps = FileUtil.readPropertiesFromFilename(OSHI_ARCHITECTURE_PROPERTIES);
            String vendor = archProps.getProperty("hw_impl." + this.cpuVendor);
            return (vendor == null ? cpuVendor : vendor);
        }

        @Override
        public String toString() {
            return getIdentifier();
        }
    }
}
